Micromirror spectrophotometer assembly

ABSTRACT

Aspects of a micromirror spectrophotometer assembly are described. In one example case, an instrument includes a diffraction grating to disperse broadband light over a range of wavelengths, a detector, a digital micromirror device (DMD) configured to scan through and reflect at least a portion of the range of wavelengths toward the detector, and a base platform having a number of integrally formed assembly mounts. The assembly mounts are formed to align and secure the diffraction grating, the detector, the DMD, and other optical components of the instrument in a predetermined arrangement. The instrument can also include a reference paddle having a reference material for calibration of the instrument, and a rotatable sample tray to rotate a sample placed on the sample tray for measurement.

BACKGROUND

Spectrophotometers can be used to measure the intensity of light as afunction of its wavelength over a spectral range of light (e.g., thespectral bandwidth of the spectrophotometer). For a spectrophotometer,important aspects of measurements include the absorption, transmittance,and reflectance of light by samples, for example, measured as apercentage or other gauge or metric. Spectrophotometers are often usedto identify or determine the quality or quantity of solutions and solidsbased on the transmittance and reflectance characteristics of thosesamples.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the embodiments described herein can be better understoodwith reference to the following drawings. The elements in the drawingsare not necessarily drawn to scale, with emphasis instead being placedupon clearly illustrating the principles of the embodiments.Additionally, certain dimensions or positionings can be exaggerated tohelp visually convey certain principles. In the drawings, similarreference numerals between figures designate like or corresponding, butnot necessarily the same, elements.

FIG. 1 illustrates an example spectrophotometer according to anembodiment described herein.

FIG. 2 illustrates a representative block diagram of the examplespectrophotometer shown in FIG. 1 according to an embodiment describedherein.

FIG. 3 illustrates a top-down view of a base platform of the measurementunit in the example spectrophotometer shown in FIG. 1 according to anembodiment described herein.

FIG. 4 illustrates a perspective view of the base platform of themeasurement unit in the example spectrophotometer shown in FIG. 1according to an embodiment described herein.

FIG. 5 illustrates a perspective view of the base platform, assemblymount cover of the base platform, and cover of the measurement unit inthe example spectrophotometer shown in FIG. 1 according to an embodimentdescribed herein.

FIGS. 6A and 6B, respectively, illustrate top and bottom views of asample platform of the example spectrophotometer shown in FIG. 1according to an embodiment described herein.

FIG. 7 illustrates a sample tray of the example spectrophotometer shownin FIG. 1 according to an embodiment described herein.

FIG. 8 illustrates an example schematic block diagram of processingcircuitry which can be employed in the spectrophotometer shown in FIG. 1according to an embodiment described herein.

DETAILED DESCRIPTION

According to aspects of the embodiments described herein, Digital LightProcessing (DLP) Digital Micromirror Device (DMD) (DLP-DMD) technologyis incorporated into a low-cost, commercial production spectrophotometerusing an integral, singular-unit base platform or chassis assembly. Thebase platform or chassis assembly includes a number of optical assemblymounts. The base platform assembly facilitates the assembly of optics ina predetermined, pre-aligned spectrophotometer configuration for takingspectral measurements of various samples, including natural andsynthetic food and agricultural products, among others. Features of theembodiments include a simple-to-use, pre-aligned optical and electronicbase platform assembly, an automatic reference reflector, and a rotatingsample tray. The embodiments can also rely upon spectral regionmeasurement stitching, spectral and calibration transfer betweeninstruments, and the alignment of spectra with specialized wavelengthstandards, photometric standards, and lineshape correction methods.

In one example described below, an instrument includes a diffractiongrating to disperse broadband light over a range of wavelengths, adetector, a digital micromirror device (DMD) configured to scan throughand reflect at least a portion of the range of wavelengths toward thedetector, and a base platform having a number of integrally formedassembly mounts. The assembly mounts are formed to align and secure thediffraction grating, the detector, the DMD, and other optical componentsof the instrument in a predetermined arrangement. The instrument canalso include a reference paddle having a reference material forcalibration of the instrument, and a rotatable sample tray to rotate asample placed on the sample tray for measurement.

Turning to the drawings, FIG. 1 illustrates an example spectrophotometer10 according to an embodiment described herein. Before continuing with adescription of the spectrophotometer 10, it is noted that FIG. 1 isprovided as a representative example for discussion. The example shownin FIG. 1 is not necessarily drawn to scale, does not exhaustivelyillustrate every part, piece, or component of the spectrophotometer 10,and is not intended to be limiting of the embodiments. Otherarrangements of similar, additional, or fewer components can be used toachieve any number of the advantages described herein.

Among other components, the spectrophotometer 10 includes an enclosure20, a sample platform 30 positioned at a top side of the enclosure 20, apower supply module 40, a computer control module 50, a support chassis60, and a DLP-DMD measurement unit 100 (“measurement unit 100”). Themeasurement unit 100 is secured by the support chassis 60 within theenclosure 20.

The enclosure 20 can be embodied as any suitable case or enclosure,formed from plastic, metal, rubber, other materials, and/or combinationsthereof, for enclosing and securing the components of thespectrophotometer 10. Similarly, the support chassis 60 within theenclosure 20 can be formed from plastic, metal, rubber, and othermaterials suitable for supporting and securing the measurement unit 100,the sample platform 30, and other components of the spectrophotometer10, such as a monitor, keyboard, mouse, etc. Both the enclosure 20 andthe support chassis 60 can be embodied as a number of parts and/orpieces secured together using any suitable means, such as mechanicalinterferences or joints, mechanical fasteners (e.g., screws, rivets,pins, interlocks), adhesives, etc.

At the top of the enclosure 20, the sample platform 30 includes a samplewindow 32 as shown in FIG. 1. As discussed in further detail below,samples for measurement by the spectrophotometer 10 can be placed in asample cup, for example, and placed over the sample window 32 formeasurement by the measurement unit 100 of the spectrophotometer 10 andanalysis by the computer control module 50.

The power supply module 40 can be embodied as any suitable power supply(e.g., switch-mode, regulated, or other power supply) to provide powerto the computer control module 50, the measurement unit 100, and othercomponents of the spectrophotometer 10, such as stepper and/or servomotors, solenoids, relays, and fans, among other components. In thatcontext, the power supply module 40 can convert power from line voltageto lower voltage direct current power suitable for components in thespectrophotometer 10.

The computer control module 50 can be embodied as one or more circuits,processors, processing circuits, memory devices, or any combinationthereof configured to control components in the spectrophotometer 10.For example, the computer control module 50 can be configured tocapture, store, and analyze data captured by a detector in themeasurement unit 100, as described in further detail below. The computercontrol module 50 can also be configured to forward and/or display datato other computing or display device(s), receive control instructions orfeedback through I/O interfaces (e.g., keyboards, keypads, touchpads,pointing devices) of the spectrophotometer 10, and store and processvarious types of data.

FIG. 2 illustrates a representative block diagram of the examplespectrophotometer 10 shown in FIG. 1 according to an embodimentdescribed herein. In FIG. 2, a number of components of the measurementunit 100 are shown. Additionally, a representative sample tray 102,sample tray drive motor 104, reference paddle 108, and reference paddleactuator 110 are shown. In the example shown in FIG. 2, the referencepaddle 108 is positioned within the enclosure 20, and the sample tray102 is positioned outside the enclosure 20. The representative sampletray 102, sample tray drive motor 104, reference paddle 108, andreference paddle actuator 110 are described in further detail below withreference to FIGS. 6A and 6B.

Among other components, the measurement unit 100 includes a light sourceassembly 120, an optical focusing assembly 130, a diffraction grating140, another optical focusing assembly 150, a digital micromirror device(DMD) 160, an optical collimating assembly 170, and a detector 180. Thelight source assembly 120 includes a light source 122 and an entranceoptics assembly 124.

The entrance optics assembly 124 is aligned with an entrance opening 126in a cover of the measurement unit 100. During operation of thespectrophotometer 10, light from the light source 122 can travel alongan optical pathway 200 in the light source assembly 120, through thesample window 32, and illuminate a sample placed on, in, or over thesample tray 102. Light reflected (and not absorbed) off the sample cantravel along an optical pathway 202, through the entrance opticsassembly 124, and through the entrance opening 126 in the cover of themeasurement unit 100. The cover of the measurement unit 100 is describedin further detail below with reference to FIG. 5.

In one embodiment, the light source 122 can include a halogen lamp orlight bulb, although any source of broadband light suitable for theapplication can be relied upon among embodiments. The entrance opticsassembly 124 can include optical elements that collimate light reflectedoff the sample, such as one or more spaced-apart expander and/orplano-convex lenses or other elements, without limitation. The entranceopening 126 can include a slit or other opening though which at least aportion of the light reflected off the sample can be passed through thecover of the measurement unit 100. In some cases, entrance opening 126can be selectively covered and/or uncovered by a mechanical orelectrical shutter (e.g., a liquid crystal, LCD, or similar device). Theshutter can be actuated and controlled by the computer control module50, for example, during various operations of the spectrophotometer 10,such as during dark scans, calibration or reference scans, and live scanoperations, for example.

After passing through the entrance opening 126 along the optical pathway202, light reflected off the sample can pass through the opticalfocusing assembly 130 to reach the diffraction grating 140. The opticalfocusing assembly 130 can include one or more spaced-apart lenses, suchas the lenses 132 and 134 and the optical filter 136 (e.g., opticalbandwidth filter) shown in FIG. 2. As described in further detail belowwith reference to FIGS. 3-5, the lenses 132 and 134 and optical bandpassfilter 136 can be secured in an optical assembly mount of a baseplatform of the measurement unit 100.

The diffraction grating 140 can be embodied as a grating selected todisperse the light reflected off the sample into a range of wavelengthsof light. For example, the diffraction grating 140 can disperse lightover the ultra-violet (UV) to visible (VIS) range of wavelengths. Inanother case, the diffraction grating 140 can disperse light over thenear-infrared (NIR) to infrared (IR) range of wavelengths. In variousembodiments, the diffraction grating 140 can be selected to disperselight over any desired range of wavelengths.

The diffraction grating 140 can be embodied as substrates of varioussizes with parallel grooves replicated on their surfaces, as would beappreciated in the art. The diffraction grating 140 disperses the lightreflected off the sample by spatially separating it according towavelength. Various methods of manufacture of diffraction gratings areknown in the field, and the diffraction grating 140 can be manufacturedusing any known method, such as by replication from master gratings,interferometric control, holographic generation, ion etching, orlithography, for example. The diffraction grating 140 can also include acoating of reflective material over the grooves, to reflect light. Thediffraction grating 140 can be sourced from any manufacturer ofdiffraction gratings, such as Optometrics Corporation of Littleton,Mass., Grating Works of Acton, Mass., or Richardson Gratings™ ofRochester, N.Y., for example, among others.

After being dispersed by the diffraction grating 140, the lightreflected off the sample can travel through the optical focusingassembly 150 along the optical pathway 204 to reach the DMD 160. Theoptical focusing assembly 150 can include one or more spaced-apartlenses, such as the lenses 152 and 154 shown in FIG. 2. As described infurther detail below with reference to FIGS. 3 and 4, the lenses 152 and154 can be secured in an optical assembly mount of the base platform ofthe measurement unit 100.

The DMD 160 can be embodied as an array of hundreds of thousands tomillions of micromirrors. The micromirrors of the DMD 160 can becontrolled, respectively, by the computer control module 50 (and/oradditional electronic components) to scan through and reflect at least aportion of the dispersed wavelengths of light from the diffractiongrating 140 along the optical pathway 206 toward the detector 180. Usingthe DMD 160, one or more wavelengths or ranges of wavelengths can bereflected toward the detector 180 for measurement over time. Individualwavelengths or ranges of wavelengths can be selected over time (e.g.,scanned) by the computer control module 50 by selectively turningcolumns of micromirrors in the DMD 160 on or off, to reflect desiredwavelengths to the detector 180. The DMD 160 allows for the use of ahigh-performance detector 180, while providing wavelength selectionagility and speed in the spectrophotometer 10. Further, the DMD 160allows for mechanical stability in the spectrophotometer 10 because itis not necessary to pivot or rotate the diffraction grating 140 ascompared to conventional techniques.

After being reflected by the DMD 160, the light reflected off the samplecan travel through the optical collimating assembly 170 along theoptical pathway 206 to reach the detector 180. The optical collimatingassembly 170 can include one or more spaced-apart lenses, such as thelenses 172, 174, and 176 shown in FIG. 2. As described in further detailbelow with reference to FIGS. 3 and 4, the lenses 172 and 174 can besecured in an optical assembly mount of the base platform of themeasurement unit 100.

The detector 180 is configured to measure the intensity of the lightreflected off the sample (or the fraction of the light absorbed by thesample at specific wavelengths, i.e., the absorbance of the sample). Thedetector 180 further converts the light to one or more electricalsignals for analysis by the computer control module 50. In the computercontrol module 50, the electrical signals can be converted (e.g., usingone or more analog to digital converters) to data values from which aquantitative analysis of a variety of characteristics of the sample,including constituent analysis, moisture content, protein content, fatcontent, fiber content, amino acid content, taste, texture, viscosity,etc., can be determined. The detector 180 can include one or morecharge-coupled device (CCD), indium gallium arsenide (InGaAs), or otherultraviolet through infrared image or light sensors that observe thereflection of light from the sample at one or more points ofillumination. The field of view of the detector 180 can be restrictedbased on the relative geometry and/or placement of the lenses 172, 174,and 176 to maximize the collection of energy while minimizing the lightinclusion of stray light.

FIG. 3 illustrates a top-down view and FIG. 4 illustrates a perspectiveview of the base platform 300 of the measurement unit 100 in the examplespectrophotometer 10 shown in FIG. 1. The embodiment of the baseplatform 300 shown in FIGS. 3 and 4 is provided as a representativeexample. In other cases, the base platform 300 can include otherarrangements (and numbers) of assembly mounts and seats within theassembly mounts.

As shown in FIGS. 3 and 4, the base platform 300 includes a number ofassembly mounts which are described in further detail below. A number ofthe assembly mounts are aligned along (and/or interfere with) one ormore of the optical pathways 200, 202, 204, and 206. Some of theassembly mounts can be used to secure one or more lenses, opticalfilters, and/or other components in a predetermined, pre-alignedarrangement. Other assembly mounts can be used to secure one or moregratings, such as the diffraction grating 140, and electrical oroptical-electrical components, such as the DMD 160 and the detector 180.

In one aspect of the embodiments, the base platform 300 can be formed asa single, integral unit. To that end, the base platform 300 can beformed using an additive manufacturing process. Additive manufacturingprocesses include those processes by which three-dimensional (3D)objects can be formed by adding layer-upon-layer of the same material.Additive manufacturing processes include many technologies including 3Dprinting, rapid prototyping (RP), direct digital manufacturing (DDM),layered manufacturing, and additive fabrication. The process can beconducted using any suitable material, such as a plastic or polymer(e.g., acrylonitrile butadiene styrene (ABS), nylon, plastic resin,etc.), poly-foam, Delrin®, metal, etc. In other approaches, the baseplatform 300 can be formed using other manufacturing processes, such ascomputer numerical control (CNC) machining and/or tooling processes,where material is removed from a larger workpiece.

During the additive manufacturing process, the assembly mounts of thebase platform 300 can be formed to include a number of seats to secureone or more lenses, optical filters, and/or other components of themeasurement unit 100 in a predetermined, pre-aligned arrangement.Starting with the base platform 300, the measurement unit 100 of thespectrophotometer 10 can be assembled relatively quickly and easily in arepeatable fashion. Specifically, each of the lenses, optical filters,and/or other components of the measurement unit 100 can be inserted andsecured into a corresponding seat in an assembly mount of the baseplatform 300.

Each of the lenses, optical filters, and/or other components of themeasurement unit 100 may take a different form, shape, and/or size.Thus, the seats for each of the components can, similarly, take adifferent form, shape, and/or size. In some cases, each of thecomponents will fit into one and only one seat (and possibly in only oneorientation) in the base platform 300. In that case, the measurementunit 100 of the spectrophotometer 10 can be assembled in only one way.

Referring between FIGS. 3 and 4, the base platform 300 includes theassembly mounts 320, 330, 340, 350, 360, and 370, for securing the lightsource assembly 120, the optical focusing assembly 130, the diffractiongrating 140, the optical focusing assembly 150, the DMD 160, and theoptical collimating assembly 170 and detector 180, respectively. Asshown in FIG. 3, the assembly mounts 320, 330, and 340 are spaced alongthe optical pathways 200 and 202. The assembly mounts 340, 350 and 360are spaced along the optical pathway 204. The assembly mounts 360, 370,and 380 are spaced along the optical pathway 206.

To assemble the measurement unit 100, the light source 122 and theentrance optics assembly 124 can be secured within the assembly mount320 by sliding them into openings within the assembly mount 320 andsecuring them in place using mechanical interferences or joints,mechanical fasteners (e.g., screws, rivets, pins, interlocks),adhesives, etc. Similarly, the diffraction grating 140 can be securedwithin the assembly mount 340 by sliding it into the assembly mount 340and securing it in place with any suitable means. The DMD 160 can alsobe secured within or to the assembly mount 360 by sliding it into theassembly mount 340 and securing it in place with any suitable means. Asshown in FIGS. 3 and 4, the assembly mount 360 includes a number ofbaffles 362 and 364 to mitigate or block stray light within themeasurement unit 100.

The lenses 132 and 134 and the optical filter 136 of the opticalfocusing assembly 130 can be placed and secured into the seats 332, 334,and 336 of the assembly mount 320. Similarly, the lenses 152 and 154 ofthe optical focusing assembly 150 can be placed and secured into theseats 352 and 354 of the assembly mount 350. The lenses 172, 174, and176 of the optical collimating assembly 170 can also be placed andsecured into the seats 372, 374, and 376 of the assembly mount 370. Thedetector 180 can be placed and secured into the seat 378 of the assemblymount 370.

The components (e.g., lenses, filters, mirrors, gratings, detectors,etc.) of the measurement unit 100 can be secured into the seats of thebase platform 300 by being placed within and, in some cases, held inplace by mechanical contact, foam spacers, adhesives, or other means.Further, after various components have been seated into the seats 332,334, 336, 352, 354, 372, 374, and 376 of the assembly mounts 330, 350,360, and 370, the assembly mounts 330, 350, 360 and 370 can be closedusing one or more assembly mount covers, such as the assembly mountcover 400 shown in FIG. 4. The assembly mount cover 400 can includeseats corresponding in size and position with the seats 332, 334, 336,352, 354, 372, 374, and 376 of the assembly mounts 330, 350, and 370.

One or more of the assembly mounts 330, 350, and 370 can include holes(e.g., see reference 398 in FIG. 3), which can be threaded in somecases. The assembly mount cover 400 can also include holes, one of whichis designated by reference 402 in FIG. 4. After various components havebeen seated into the assembly mounts 330, 350, 360, and 370, theassembly mount cover 400 can be placed over the assembly mounts 330,350, and 370. Among other fasteners, a mechanical fastener, such as ascrew, can be passed through the hole 402 of the assembly mount cover400 and threaded into the hole 398 (see FIG. 3) of the assembly mount350 for securing the assembly mount cover 400 over the assembly mounts330, 350, and 370.

In one example case, each of the seats 332, 334, 336, 352, 354, 372,374, and 376 is formed to have a predetermined size (e.g., length,width, height, radius of curvature, etc.) for a particular one of thecomponents of the measurement unit 100. Further, the placement of eachof the components can be predetermined in a particular spaced-apartarrangement defined by the base platform 300 with respect to one or moreof the optical pathways 200, 202, 204, and 206. For example, as shown inFIG. 3, the seats 372 and 374 are spaced apart by the distance “A” alongthe optical pathway 206, and the seats 374 and 376 are spaced apart bythe distance “B” along the optical pathway 206. In other embodiments,any of the seats shown in FIGS. 3 and 4 can be spaced-apart by otherdistances depending upon the types and arrangements of the components ofthe measurement unit 100.

Again, once the base platform 300 is formed, the measurement unit 100can be assembled relatively quickly and easily as each of the lenses,optical filters, and other components of the measurement unit 100 can beinserted and secured into a corresponding assembly mount and/or seat ofthe base platform 300. In some cases, each of the components will fitinto one and only one assembly mount and/or seat (and possibly in onlyone orientation) in the base platform 300. In that case, the measurementunit 100 of the spectrophotometer 10 can be assembled in only one way.As compared to conventional techniques without the use of a baseplatform as described herein, it can be relatively time consuming anddifficult to ensure that all the components of a spectrophotometer arealigned properly.

The base platform 300 also includes number of standoffs 390-393 andeyelets 394 and 395 as shown in FIG. 3. As described in further detailbelow with reference to FIG. 5, a cover can be mounted over the baseplatform 300, seated into and against the channel 396 along a length ofthe bottom edge of the base platform 300, and secured against the topends of the standoffs 390-393 using screws or other mechanical fasteningmeans. When the measurement unit 100 is fully assembled and the cover ofthe base platform 300 is secured, the measurement unit 100 can besecured to the support chassis 60 within the enclosure 20 of thespectrophotometer 10 as shown in FIG. 1. The eyelets 394 and 395 can beused to pass wiring assemblies, harnesses, etc. between the componentsinside the measurement unit 100, the power supply module 40, and thecomputer control module 50.

Before turning to FIG. 5, it is again noted that the base platform 300illustrated in FIGS. 3 and 4 is provided as a representative example.Other base platforms for other instruments can include other numbers andarrangements of assembly mounts. In that sense, other base platforms caninclude assembly mounts aligned along optical pathways other than thoseshown in FIGS. 3 and 4. For example, although the optical pathways 202and 206 extend parallel to each other, and the optical pathway 202extends at an angle ϕ with respect to the optical pathway 204, assemblymounts can be formed at other positions in a base platform for alignmentto other optical pathways at other angles with respect to each other inany suitable manner.

FIG. 5 illustrates a perspective view of the base platform 300, assemblymount cover 400 of the base platform 300, and cover 500 of themeasurement unit 100 in the example spectrophotometer 10 shown inFIG. 1. As described above, the base platform 300 includes a number ofstandoffs 390-393. After the assembly mount cover 400 is secured to thebase platform 300, the cover 500 can be mounted over the base platform300, seated into and against the channel 396 along a length of thebottom edge of the base platform 300, and secured against the top endsof the standoffs 390-393 using screws or other mechanical fasteningmeans passed through holes 501-504 in the cover 500. When themeasurement unit 100 is fully assembled and the cover 500 of the baseplatform 300 is secured, the measurement unit 100 can be secured to thesupport chassis 60 within the enclosure 20 of the spectrophotometer 10.

FIGS. 6A and 6B, respectively, illustrate top and bottom views of asample platform 30 of the example spectrophotometer 10 shown in FIG. 1.As shown in FIG. 6A, the sample platform includes the sample window 32.Light from the light source assembly 120 can pass through the samplewindow 32 and exit the enclosure 20 of the spectrophotometer 10 alongoptical pathway 200 (FIG. 2). As also described in further detail belowwith reference to FIG. 7, light that passes through the sample window 32can illuminate a sample placed on, in, or over the sample tray 102 abovethe sample window 32. Light reflected (and not absorbed) off the samplecan travel back through the sample window 32 and into the measurementunit 100.

Referring to FIG. 6B, a motor 600 is secured to the bottom side of thesample platform 30. A stepper or servo motor 630 is also secured to thebottom side of the sample platform 30. As described in further detailbelow with reference to FIG. 7, the computer control module 50 can alsocontrol the servo motor 630 to rotate a sample tray 102 placed over thesample window 32 in the sample platform 30.

A reference paddle 610 is mechanically secured to a shaft of the motor600. When assembled with the motor 600 to the sample platform 30, thereference paddle 610 occupies a recess 620 in the bottom of the sampleplatform 30. The computer control module 50 can control the motor 600 torotate the reference paddle 610 between a first position 622 in therecess 620 and a second position 624 in the recess 620.

In the first position 622 shown in FIG. 6B, the reference paddle 610covers the sample window 32. As such, it interferes with the opticalpathway 200 (FIG. 2). In the first position 622, light from the lightsource assembly 120 falls upon and is reflected off of the referencepaddle 610 rather than passing through the sample window 32. Thereference paddle 610 includes a recessed area 612 for a reflectivereference material. In one embodiment, the recessed area 612 can becovered in gold plating reflective reference material for calibration ofthe spectrophotometer 10. In other embodiments, the recessed platingarea 612 can be covered or plated using other reference materials, suchas polytetrafluoroethylene (PTFE), teflon, reflective metal(s), or adiffuse mirrored surface material, among others.

FIG. 7 illustrates the sample tray 102 of the example spectrophotometer10 shown in FIG. 1. The sample tray 102 is mechanically coupled to ashaft of the stepper or servo motor 630 (FIG. 6B) through the sampleplatform 30, and the computer control module 50 can also control theservo motor 630 to rotate the sample tray 102. Thus, the sample tray 102can be rotated at the direction of the computer control module 50.

The sample tray 102 includes a sample cup adapter 700 mounted andsecured thereto. As shown in FIG. 7, the sample cup adapter 700 ismounted to the sample tray 102 above the sample window 32. When a samplefor measurement is placed in or on the sample cup adapter 700, possiblyin a sample cup or other fixture, it can be rotated. In other words,sample cup adapter 700 can be rotated along with the sample tray 102using the stepper or servo motor 630. The sample cup adapter 700 can berotated at different (or variable) speeds, for example, from a fewdegrees per second to about 180 degrees per second based on controlprovided by the computer control module 50.

By rotating the sample during measurements taken by thespectrophotometer 10, measurements can be taken in a more representativeand/or comprehensive manner because light can be reflected (or absorbed)off the sample at different times or over time from different positionsor orientations of the sample.

In some embodiments, one or more aspects of spectral region measurementstitching, spectral and calibration transfer between instruments, andthe alignment of spectra with specialized wavelength standards,photometric standards, and lineshape correction methods can beincorporated into the spectrophotometer 10. For example, the aspectsdescribed in any of U.S. patent application Ser. No. 13/829,651, titled“SPECTROMETER SECONDARY REFERENCE CALIBRATION”; U.S. patent applicationSer. No. 14/600,454, titled “SPECTROMETER REFERENCE CALIBRATION”; U.S.Pat. No. 9,404,799, titled “TANDEM DISPERSIVE RANGE MONOCHROMATOR”; orU.S. patent application Ser. No. 15/416,552, titled “DATA BLENDINGMULITPLE DISPERSIVE RANGE MONOCHROMATOR” can be incorporated into thespectrophotometer 10. The entire disclosures of each of U.S. patentapplication Ser. No. 13/829,651; U.S. patent application Ser. No.14/600,454; U.S. Pat. No. 9,404,799; and U.S. patent application Ser.No. 15/416,552, titled “DATA BLENDING MULITPLE DISPERSIVE RANGEMONOCHROMATOR” are hereby incorporated herein by reference.

FIG. 8 illustrates an example schematic block diagram of processingcircuitry which can be employed as the computer control module 50 in thespectrophotometer 10 shown in FIG. 1 according to an embodimentdescribed herein. The processing circuitry 800 can be embodied, in part,using one or more elements of a general purpose or specialized embeddedcomputer. The processing circuitry 800 includes a processor 810, aRandom Access Memory (RAM) 820, a Read Only Memory (ROM) 830, a memorydevice 840, and an Input Output (“I/O”) interface 850. The elements ofthe processing circuitry 800 are communicatively coupled via a localinterface 802. The elements of the processing circuitry 800 describedherein are not intended to be limiting in nature, and the processingcircuitry 800 can include other elements.

In various embodiments, the processor 810 can comprise any well-knowngeneral purpose arithmetic processor, programmable logic device, statemachine, or Application Specific Integrated Circuit (ASIC), for example.The processor 810 can include one or more circuits, one or moremicroprocessors, ASICs, dedicated hardware, or any combination thereof.In certain aspects embodiments, the processor 810 is configured toexecute one or more software modules. The processor 810 can furtherinclude memory configured to store instructions and/or code to variousfunctions, as further described herein. In certain embodiments, theprocessor 810 can comprise a general purpose, state machine, or ASICprocessor, and various processes can be implemented or executed by thegeneral purpose, state machine, or ASIC processor according softwareexecution, by firmware, or a combination of a software execution andfirmware.

The RAM and ROM 820 and 830 can comprise any well-known random accessand read only memory devices that store computer-readable instructionsto be executed by the processor 810. The memory device 840 storescomputer-readable instructions thereon that, when executed by theprocessor 810, direct the processor 810 to direct the spectrophotometer10 to perform various aspects of the embodiments described herein.

As a non-limiting example group, the memory device 840 can comprise oneor more non-transitory devices or mediums including an optical disc, amagnetic disc, a semiconductor memory (i.e., a semiconductor, floatinggate, or similar flash based memory), MLC Negative-AND-based flashmemory, a magnetic tape memory, a removable memory, combinationsthereof, or any other known memory means for storing computer-readableinstructions. The I/O interface 850 can comprise device input and outputinterfaces such as keyboard, pointing device, display, communication,and/or other interfaces, such as a network interface, for example. Thelocal interface 802 electrically and communicatively couples theprocessor 810, the RAM 820, the ROM 830, the memory device 840, and theI/O interface 850, so that data and instructions can be communicatedamong them.

In certain aspects, the processor 810 is configured to retrievecomputer-readable instructions and data stored on the memory device 840,the RAM 820, the ROM 830, and/or other storage means, and copy thecomputer-readable instructions to the RAM 820 or the ROM 830 forexecution, for example. The processor 810 is further configured toexecute the computer-readable instructions to implement various aspectsand features of the embodiments described herein.

Although embodiments have been described herein in detail, thedescriptions are by way of example. The features of the embodimentsdescribed herein are representative and, in alternative embodiments,certain features and elements can be added or omitted. Additionally,modifications to aspects of the embodiments described herein can be madeby those skilled in the art without departing from the spirit and scopeof the present invention defined in the following claims, the scope ofwhich are to be accorded the broadest interpretation so as to encompassmodifications and equivalent structures.

At least the following is claimed:
 1. An instrument, comprising: adiffraction grating to disperse broadband light over a range ofwavelengths; a detector; a digital micromirror device (DMD) configuredto scan through and reflect at least a portion of the range ofwavelengths toward the detector; and a plurality of assembly mountsintegrally formed as a base platform to align and secure the diffractiongrating, the detector, the DMD, and a plurality of optical components ofthe instrument in a predetermined arrangement, wherein: the plurality ofthe assembly mounts comprise a plurality of integral seats to align andsecure the plurality of optical components of the instrument in apredetermined arrangement relative to each other and the diffractiongrating, the detector, and the DMD; and the plurality of integral seatsare individually separated by a predetermined spacing along at least oneoptical pathway in the instrument.
 2. The instrument of claim 1, whereinat least one of the plurality of assembly mounts comprises: a firstintegral seat formed for a first optical component of a focusing opticsassembly; and a second integral seat for a second optical component ofthe focusing optics assembly, the first integral seat and the secondintegral seat being separated by a predetermined spacing along anoptical pathway that extends along the at least one of the plurality ofassembly mounts.
 3. The instrument of claim 1, wherein: a first of theplurality of assembly mounts is aligned along a first optical pathway inthe instrument; a second of the plurality of assembly mounts is alignedalong a second optical pathway parallel to the first optical pathway inthe instrument; and a third of the plurality of assembly mounts isaligned along a third optical pathway at an angle with respect to atleast one of the first optical pathway and the second optical pathway inthe instrument.
 4. The instrument of claim 3, wherein: the plurality ofoptical components are aligned and secured in the first, second, andthird of the plurality of assembly mounts; and an assembly mount coveris secured over the first, second, and third of the plurality ofassembly mounts.
 5. The instrument of claim 3, wherein a fourth of theplurality of assembly mounts is aligned at one end of the first opticalpathway to secure a light source and an entrance optics assembly of theinstrument.
 6. The instrument of claim 5, wherein a fifth of theplurality of assembly mounts is positioned about an intersection of thefirst optical pathway and the second optical pathway to secure thediffraction grating.
 7. The instrument of claim 6, wherein: a sixth ofthe plurality of assembly mounts is positioned about an intersection ofthe second optical pathway and the third optical pathway to secure theDMD; and the sixth of the plurality of assembly mounts includes a numberof baffles integral to the base platform.
 8. The instrument of claim 1,wherein the base platform is continuously formed from a single materialusing an additive manufacturing process.
 9. The instrument of claim 1,further comprising: a motor comprising a shaft; and a reference paddlemechanically coupled to the shaft of the motor, wherein: the referencepaddle includes a reference material for calibration of the instrument;and the motor is configured to rotate the reference paddle to cover asample window of the instrument for calibration of the instrument. 10.The instrument of claim 1, further comprising: a motor comprising ashaft that extends through a sample platform 30 of the instrument; and asample tray mechanically coupled to the shaft of the motor, wherein themotor is configured to rotate a sample placed on the sample tray formeasurement.
 11. A method of assembly for an instrument, comprising:forming a base platform comprising a plurality of integral assemblymounts; securing a diffraction grating in a first of the plurality ofintegral assembly mounts; securing a digital micromirror device (DMD) ina second of the plurality of integral assembly mounts; securing adetector in a third of the plurality of integral assembly mounts; andseating at least one optical component of the instrument in a fourth ofthe plurality of integral assembly mounts, wherein the diffractiongrating, the DMD, the detector, and the at least one optical componentare aligned and secured in a predetermined arrangement based on relativepositions of the plurality of integral assembly mounts of the baseplatform.
 12. The method of assembly for the instrument of claim 11,further comprising installing a cover over the base platform.
 13. Themethod of assembly for the instrument of claim 11, further comprisinginstalling an assembly mount cover over the fourth of the plurality ofintegral assembly mounts.
 14. The method of assembly for the instrumentof claim 11, wherein: the first of the plurality of integral assemblymounts is aligned along a first optical pathway in the instrument; andthe second of the plurality of integral assembly mounts is aligned alonga second optical pathway parallel to the first optical pathway in theinstrument.
 15. The method of assembly for the instrument of claim 11,wherein forming the base platform comprises forming the base platformusing an additive manufacturing process.
 16. An instrument, comprising:a diffraction grating to disperse broadband light over a range ofwavelengths; a detector; a digital micromirror device (DMD) configuredto scan through and reflect at least a portion of the range ofwavelengths toward the detector; and a plurality of assembly mountsintegrally formed as a base platform to align and secure the diffractiongrating, the detector, the DMD, and at least one optical component ofthe instrument in a predetermined arrangement.
 17. The instrument ofclaim 16, wherein at least one of the plurality of the assembly mountscomprises a seat to align and secure the at least one optical componentof the instrument in a predetermined arrangement relative to thediffraction grating, the detector, and the DMD.
 18. The instrument ofclaim 17, wherein the at least one of the plurality of the assemblymounts comprises: a first integral seat formed for a first opticalcomponent of an optics assembly; and a second integral seat for a secondoptical component of the optics assembly, the first integral seat andthe second integral seat being separated by a predetermined spacingalong an optical pathway in the instrument.
 19. The instrument of claim16, wherein the base platform is continuously formed from a singlematerial using an additive manufacturing process.
 20. The instrument ofclaim 1, further comprising: a motor comprising a shaft; and a referencepaddle mechanically coupled to the shaft of the motor, wherein: thereference paddle includes a reference material for calibration of theinstrument; and the motor is configured to rotate the reference paddleto cover a sample window of the instrument for calibration of theinstrument.